1. Field
This invention relates to necked container filling machines principally those of the carousel type, and particularly concerns unique cam operated actuators for use with fill valves for beverage bottles, cans or the like wherein each actuator employs a camshaft provided with O-ring seals which slidably rotatably mount the camshaft in the bore of an actuator barrel (shaft housing) for rotative motion therein whereby each cam which is inside the fill tank can contact a cam follower on a fill valve and progressively urge the valve between an open filling position and a closed position.
2. Prior Art
Conventional fluid filling machines such as are used for filling beer or soft drink bottles typically are constructed to provide multiple filling stations which move along in a continuous conveyor-like manner, e.g., in a circle, and while so moving, progressively perform various operations leading to filling of the bottles. With such machines, conveyor systems are provided for bringing empty bottles to the machines and for removing filled bottles therefrom.
Typical of such filling machines is the carousel type shown and described in detail in the service manual entitled EUROSTAR BOTTLE FILLER, SERVICE MANUAL. Copyright 1980 TECHNAPAC, Inc. The Barry-Wehmiller Company, 318 pages, and particularly on pages 1-1, 1-2, and 2-1 thru 2-14 thereof, the disclosure of which manual is hereby incorporated herein in its entirety. In these machines, particularly the ones relevant here, a large circular fill tank rotates on a horizontal base and carries a large number of fill valves and cam type actuators therefor, which actuators are mounted on and extend thru a peripheral wall of the fill tank. The outer end of each actuator is provided with a lever (46 in the present drawings) which when struck by a shoulder means affixed to said base will rotate the actuator to open or close the fill valve in a predetermined sequence as the fill tank and its accouterments rotate.
For further background information the progressive operations of such machines as described above are shown in schematic form in FIGS. 8 and 9 herein marked Prior Art, and with the operations approximately delineated by position and numbered progressively Op. #1 thru Op. #5. In FIG. 9 the circular or rotational actions of the machine of FIG. 8 are depicted in linear form for clarification.
In these figures Op. #1 brings the bottles 11 to Op. #2 in feed star wheel A which moves the bottles in a circle toward the tangential junction area B of star wheel A and in registry with the moving bottle supports or pads C (only one shown in dotted line) of the rotating carousel. After each bottle is positioned by star wheel A on a support C, the bottle is lifted vertically in Op. #3 by a support cylinder (e.g., air) and the bottle neck top D is engaged, captured and sealed at J by a centering cup E shown in simplistic form. Referring to FIG. 8 elevation of support C in Op. #4A, moves the bottle 11 and cap E upwardly to a point where a seal unit F in the centering cup is pressed against neck top D and a sealing surface G surrounding a fill port H on a filler bowl or tank 13 on the machine. Typically at this stage (#4B) the air in the bottle is evacuated and then pressure equalization in the bottle and fill bowl is performed at Op. #4C, and filling of the bottle takes place at Op. #4D. When the filling is completed, the support C is moved downwardly in Op. #5, typically by a cam ramp provided on a non-rotating structure of the machine and engageable with a cam follower on support C. With the bottle now in its retracted position, it is captured in another star wheel J tangentially of the carousel and moved onto further processing operations such as bottle sniffing and capping.
It is particularly noted that depending on the type and make of filling machine, the location of the various operations described above may be different, however, the present invention is applicable to any such machine.
One type of cam assembly presently also termed “actuator”, has a camshaft typically substantially free floating at its cam end and is engineered in a way that one actuator is placed above each fill valve in existing beverage filler machines with its cam aligned with a cam follower on the fill valve. The cam of the actuator is intended to open the particular fill valve it is associated with when the camshaft is rotated in one direction to allow the proper amount of liquid to enter the can or bottle and then to close the fill valve when the camshaft is rotated in the opposite direction.
This assembly, heretofore, would need continual greasing of the O-ring seals and wall portions of the barrel bore against which the seals rub during camshaft rotation with a food grade lubricant but would still wear the seals and wall portions because of the overhung (free floating) load on the cam end of the camshaft which results in wobbling of the camshaft and causes the net contents to vary in the bottle or can.
The resolution of this problem has been to periodically replace the cam assembly (actuator), an expensive and time consuming measure, however, even then the grease situation ruins the integrity of the beverage. This process of lubrication is time consuming and most of all has been quite essential to maintaining desired net contents of the can or bottle.
Another type of actuator is disclosed in U.S. Pat. Nos. 5,642,764 and 5,586,379 wherein the distal (cam lobe end) end of the camshaft is supported by a cone-shaped bearing structure. This type of bearing can prevent wobbling of the camshaft only for a very limited period of use before any wear of the moving parts of the actuator allows even the slightest axial movement of the camshaft end away from the end plate. It is particularly noted that such a bearing structure requires extremely precise control over preventing axial dislocation of the camshaft end from the end plate during installation since any such dislocation would immediately result in wobbling of the camshaft as the resilient O-ring seals would deform—however slightly.
A typical bottle filling machine and its fill valve structure and operation are shown, in general, in U.S. Pat. Nos. 5,642,764; 6,038,833; 4,086,943; and 5,586,379, the disclosures of which are hereby incorporated herein by reference in their entireties.
The present invention has as its objects and resides in a unique mounting and O-ring seal arrangement for the actuator camshaft which provides for:
improved shaft seal and barrel bore wall wear longevity in particular;
elimination of need for shaft lubrication oils or greases such that product integrity is not compromised;
greater concentricity stabilization of the camshaft under extended periods of operation and thusly markedly improved filling integrity;
more positive camshaft support, i.e., larger journal-bearing area for the inner (beverage tank) end of the camshaft which can accommodate, with ease, any axial motion between the barrel and the camshaft;
large cost reduction for actuator parts replacement;
reduction in number of parts and cost of manufacture for the actuator such as by elimination of sleeves, bushings and the like;
improved O-ring structure, in particular extra O-ring grooves in the camshaft such that new O-rings can be added to rub against new land areas of the barrel bore wall which greatly increases barrel life; and overall simplification of structural design of the actuator.